The practice of the pereception of body consists in concentrating the mind on each part of the body, one by one and perceiving the sensations and vibrations taking place in each part.
Of course, here the perception does not mean the visual perception, but the mental one.
The sensations may be superficial sensations of the skin such as the contact with your clothes warmth or coolness, itching and perspiration etc, or they may be the sensations of pain, numbness, tingling etc. felt in the muscles or the vibrations of the electrical impulses in the nervous system or any other type of vibrations.
Starting from the surface you have to penetrate deeply inside and try to become aware of the internal and subtle vibrations.
Remain completely equanimous towards the sensations; try to keep your mind free from like or dislike.

A third step of preksha meditationis perception of body(alternative, see: [3][3A][3B][3C])

Concentrate your mind on the big toe of your right foot. Allow it to spread and permeate throughout the whole portion of the toe. Perceive the sensations and vibrations taking place in that region. Become aware of them, experience them without any like or dislike; use deep concentration and remain fully alert.

Now shift your attention to each part of right limb one by one. I shall now indicate the name of the part of your body on which you have to concentrate your mind and perceive it: The other toes, the sole, the heel, the ankle, the upper part of the foot, the calf-muscles, the knee, the thigh, upto the hip-joint. Perceive the whole part, experience the sensations and vibrations taking place in each part. Maintain equanimity.

In the same way practice perception of all the parts of your left limb.
Thus the trip of the lower body is completed.

Now, start the trip of the middle body from the waist upto the neck.
Concentrating your mind on each part one by one--perceive the waist, the navel, the abdomen including the big intestine, the small intestine, the kidney, the spleen, the liver, the pancreas, the duodenum, the stomach and the diaphragm. Then the whole portion of the chest including the lungs, the heart, the ribs, the throat and the vocal cords. Concentrate your mind and perceive.

Then practice the perception of the whole portion of the back including the spine, the spinal cord and the neck.

Now concentrate on the whole portion of the right hand and arm including the thumb, the finger, the palm, the wrist, the lower arm, the elbow, the upper arm and the shoulder. Perceive each part one by one. In the same way concentrate on the left hand and arm.
The trip of the middle body is completed.

Now we come to the upper body.
Concentrate your mind on each part from the chin upto the head. The chin, the lips, the inner portion of the mouth including the tongue, the teeth, the palate, the cheeks, the nose, the right ear, all the three parts---the outer, the middle and the inner, the right temple, in the same way the left ear and the left temple, the right eye, the left eye, the forehead and the head. Perceive each part one by one. During the perception of the tongue allow your tongue to remain hanging freely, without touching anywhere inside the mouth.

While perceiving the head, perceive all parts of your brain -
the front, the back, the right, the left, the outer and the inner. Allow your mind to permeate throughout the brain. The trip of the upper body is completed.

Now practice the perception of body as a whole.
You may stand up slowly and carefully, keeping your eyes closed. Allow your mind to travel from the big toes to the head and from the head to the big toes, rather speedily. Passing through each part of the body, perceive the vibrations throughout the body. Experience a tingling sensation in each and every muscle, skin, nerve and cell produced by the contact of your conscious mind. You may also practice the holding of breath for a while intermittently.
Get yourself completely absorbed in the perception of body.

Now allow your mind to travel throughout the body rather slowly. If you experience pain or any other peculiar sensation, you may stop there for a while and perceive it with equanimity without any like or dislike.

The Journey of Meditation

There are two levels of Consciousness: Sensory perception and Extra sensory perception. We usually live more on the level of sensory perception. To understand sensory perception, a little analysis is necessary. Our five senses are -sense of Touch, Taste, Smell, Sight and Hearing.

Scientific breathing begins with a slow, calm and complete exhalation. Contraction of the abdominal muscles helps to evacuate the lungs by raising the diaphragm. Having emptied the lungs, the next step is to fill it up to the maximum extent.